POS0938 MAINTENANCE OF RESPONSE TO BIMEKIZUMAB OVER 3 YEARS OF TREATMENT IN PATIENTS WITH ACTIVE ANKYLOSING SPONDYLITIS: POST HOC ANALYSES FROM THE BE AGILE STUDY AND ITS OPEN-LABEL EXTENSION
Authors: V. Navarro-Compán, M. Rudwaleit, N. De Peyrecave, C. Fleurinck, M. Oortgiesen, V. Taieb, X. Baraliakos
Journal: Annals of the Rheumatic Diseases (2022)

Background Bimekizumab (BKZ), a monoclonal IgG1 antibody that selectively inhibits interleukin (IL)-17F in addition to IL 17A, has demonstrated significant and rapid efficacy in patients (pts) with active ankylosing spondylitis (AS) treated for up to 48 weeks (wks) in the phase 2b BE AGILE study. 1 Maintaining stringent disease control is an internationally recognised treatment target in spondyloarthritis and a relevant goal in clinical research. 2 Objectives To report on the maintenance of clinical response, including the achievement of sustained remission or low disease activity (LDA), to support and extend previous findings on the long-term efficacy of BKZ in pts with active AS treated for up to 3 years (yrs) in BE AGILE and its open-label extension (OLE). 3 Methods Study design of the 48-wk BE AGILE study ( NCT02963506 ) and its ongoing 4-yr OLE ( NCT03355573 ) have been reported previously. 1,3 During the OLE, pts received BKZ 160 mg every 4 wks (Q4W) regardless of prior dosing. In this post hoc study, maintenance of response analyses through 156 wks were conducted for Ankylosing Spondylitis Disease Activity Score (ASDAS) &lt;2.1 and Assessment in SpondyloArthritis international Society 40 (ASAS40) response. ASDAS &lt;2.1 includes both ASDAS-LDA (1.3–&lt;2.1) and ASDAS inactive disease (ID; &lt;1.3). Data from pts randomised at baseline to BKZ 160 mg and 320 mg Q4W were used for these analyses. ASDAS and the ASAS components were assessed at every study visit to Wk 24, then every 12 wks. All reported analyses are observed case. Results At baseline, 121/303 pts were randomised to BKZ 160 mg (n=60) or 320 mg (n=61). Overall, 36/121 (29.8%) had ASDAS high disease (HD) and 84/121 (69.4%) had very high disease (VHD) activity. At Wk 12, 48/119 (40.3%) had achieved ASDAS &lt;2.1, increasing further to 66/111 (59.5%) at Wk 48 and 63/93 (67.7%) at Wk 156, of which 32 pts (32/63; 50.8%) had ID. Improvement in ASDAS was consistent across both BKZ 160 mg and 320 mg groups, with treatment response levels maintained following dose reduction to 160 mg at Wk 48 in the 320 mg group (Figure 1). Of those pts who achieved ASDAS &lt;2.1 at Wk 12 across both groups, 33/37 (89.2%) maintained ASDAS &lt;2.1 at Wk 156. In the most stringent maintenance of response analysis, 24/37 (64.9%) pts who achieved ASDAS &lt;2.1 at Wk 12 maintained this state at every ASDAS assessment during Wks 12–156. Efficacy measured by ASAS40 response was also sustained over 3 years, with 56/119 (47.1%) pts having achieved ASAS40 at Wk 12, 72/111 (64.9%) at Wk 48 and 69/96 (71.9%) at Wk 156. In line with ASDAS &lt;2.1, of those pts who achieved ASAS40 at Wk 12, 44/47 (93.6%) maintained ASAS40 at Wk 156, and 36/47 (76.6%) had maintained ASAS40 at every assessment during Wks 12–156. Conclusion BKZ 160 mg Q4W provided a robust maintenance of disease control over 3 yrs in pts with active AS who initially responded at Wk 12, irrespective of the initial dosing regimen (BKZ 160 mg or 320 mg Q4W). References [1]van der Heijde D. Ann Rheum Dis 2020;79:595–604; 2. Smolen J. Ann Rheum Dis 2018;77:3–17; 3. Gensler L. Arthritis Rheumatol 2021;73(suppl 10):0491. Acknowledgements This study was funded by UCB Pharma. Editorial services were provided by Costello Medical. Disclosure of Interests Victoria Navarro-Compán Speakers bureau: AbbVie, Eli Lilly, Janssen, MSD, Novartis, Pfizer, UCB Pharma, Consultant of: AbbVie, Eli Lilly, MSD, Novartis, Pfizer, UCB Pharma, Grant/research support from: AbbVie and Novartis, Martin Rudwaleit Speakers bureau: AbbVie, BMS, Boehringer Ingelheim, Chugai, Eli Lilly, Janssen, Novartis, Pfizer, UCB Pharma, Paid instructor for: Janssen, Novartis, UCB Pharma, Consultant of: AbbVie, Novartis, UCB Pharma, Natasha de Peyrecave Employee of: UCB Pharma, Carmen Fleurinck Employee of: UCB Pharma, Marga Oortgiesen Employee of: UCB Pharma, Vanessa Taieb Employee of: UCB Pharma, Xenofon Baraliakos Speakers bureau: AbbVie, BMS, Chugai, Eli Lilly, Galapagos, Gilead, MSD, Novartis, Pfizer, UCB Pharma, Paid instructor for: AbbVie, BMS, Chugai, Eli Lilly, Galapagos, Gilead, MSD, Novartis, Pfizer, UCB Pharma, Consultant of: AbbVie, BMS, Chugai, Eli Lilly, Galapagos, Gilead, MSD, Novartis, Pfizer, UCB Pharma